Method of manufacturing variable knop yarn

ABSTRACT

A method of making a variable knop yarn wherein a first filamentary component is passed from a feed means through, in a sequence, a heating zone, a false twist zone and a knop forming zone to a withdrawing means, and a second filamentary conponent is introduced in between said feed means and said false twist zone in such a manner that it becomes wrapped around said first filamentary component, said second component being formed into knops by being rubbed back along the first component.

United States Patent Jenkins Oct. 28, 1975 METHOD OF MANUFACTURING 3,113,413 12/1963 Jacobs et al. 57/140 J x VARIABLE YARN 333'??? 1311323 152 5 1?" 331123 ars a Inventor: Michael Anthony J 3,438,194 4/1969 Cerutti et al 57/157 R Pontypool, England 3,640,064 2/1972 Palm et al. 57/140 I X 3,685,268 8/1972 Sequin i 57/160 X [73] Asslgnee. Emil-e12! 52:52: E g gi 3,756,005 9/1973 Sequin 57/34 R [22] Filed: Aug. 9, 1973 Primary Examiner-Donald E. Watkins [21] Appl No 386 879 Attorney, Agent, or Firm-Cushman, Darby &

Cushman [30] Foreign Application Priority Data [57] ABSTRACT A 15,1972 U 'I; d K' d 38003 72 ug m e, mg om I A method of making a variable knop yarn wherein a 52 us. 01. 57/157 Ts- 57/34 115- 57/160 first filamentary is Passed {mm a feed 51 Int. Cl. 001117/92- 1301 14 13/10 means hmugh, a sequence a heating Zone a false [58] Field of Search .57 34 R 34 HS 34 B twist and a knop firming to a Withdrawing 57/77 means, and a second filamentary component is intro- 57/156 157 R 157 F 157 MS 6 b duced in between said feed means and said false twist 28 g 1 72 zone in such a manner that it becomes wrapped around said first filamentary component, said second [56] References Cited component being formed into knops by being rubbed UNITED STATES PATENTS back along the first component. 2,731,789 1/1956 Holder 57/160 6 Claims, 2 Drawing Figures U.S. Patent Oct. 28, 1975 Sheet1of2 3,914,930

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U.S. Patent Oct. 28, 1975 Sheet2of2 3,914,930

PIC-1.2.

METHOD OF MANUFACTURING VAiRIABLE KNOP YARN The present inventionconcerns variable knop yarns and methodsfor their manufacture. By a variable knop yarn we mean a .yarn which Contains prominent bunches of one or more of its components arranged at irregular intervals along its length.

According to one embodiment of the invention, we provide a. process for making a variable, k'nop yarn wherein a first filamentary component is passed from a feed means through, in sequence, a heating zone, a zone in which false twist is applied to the yarn and a knop-forming zone to a withdrawing means and a second filamentary component is introduced in a region between said feed means and said zone in which false twist is applied, preferably between said feed means and said heating zone, in such a manner that it becomes wrapped around said first filamentary component, said second filamentary component being formed into knops in the knop-forming zone by being rubbed back along said first component.

The invention also includes variable knop-type yarns made according-to the process of the invention.

By a feed means we include a positive feed system such as a nip roll or feed roll assembly or afree feed system suchas a tensioning device.

The second filamentary component may be introduced by positive feed or free feed.

The first filamentary componentmay comprise a synthetic monofilament, a continuous multifilament yarn, a bonded yarn, or a combination of any one with discontinuous fibres. A

The second filamentary component may comprise a continuous filament(s) or discontinuous fibres or a combination of both.

The false twist may be applied by a twist pin or a twist element of-the friction type by which false twist is inserted by the direct action of rotating annular friction means on the yarn.

The knops areformed in the knopsforming zone by a means which may comprise ;a friction device such as, for example, a ceramic guide. I

Variations in the size of the knops and their frequency along the yarn may be achieved by, altering the feed rate of the second filamentary component, altering the frictional properties of the knop-forming means or altering the decitex of the second filamentary com ponent. Thus, decreasing the feed rate of the second component for a given system, increasing the frictional properties of the knop-forming means or increasing the decitex of the second component tends to produce larger knops.

The region in which the second filamentary compo nent wraps around the first filamentary component may be located by positioning a thread guide or guides downstream of the feed means such that wrapping takes place between the feed means and the thread guide or between the thread guides. guide The invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic representation of one embodiment of the process of the invention.

FIG. 2 is a perspective view of the knop-forming guide 25 in FIG. 1.

A first multifilament yarn l is withdrawn from supply package 3 via a tensioner 4 and a thread guide 5 by a nip roll assembly 7. The nip roll assembly 7 comprises two continuous rolls 9 and 11 between which the yarn l is passed. From the nip roll assembly 7 the yarn 1 passes via a thread guide 13 to a false twisting stage comprising a heater place 15 and a false twist pin 17. Twist inserted by false twist pin 17 runs back along the yarn to nip roll assembly 7.

A second multifilament yarn 19 is withdrawn at a low tension from supply package 21 via athread guide 23 and wraps in a unidirectional helix around yarn l in the region between the nip roll assembly 7 and the thread guide 13. The point at which the yarn l9 wraps around the yarn 1 oscillates to and fro in a zone within this region.

In the twist zone between thread guide 13 and falsethecore. The sheath now exhibits areas with S twist and areas with Z twist, these areas of opposite twist being separated by areas in which the sheath has very little twist. v.

From the false twist pin 17, thecore yarn passes over a friction guide 25, through a nip roll assembly 27, comprising two contiguous rolls 29 and 31, and is finally wound up on package 33. At friction guide 25 the sheath is rubbed back into knops 35 along the core until the frictional force between the guide 25 and the knop is below the force needed to rub back the sheath; the knop 35 is then released from the friction guide 25: and travels with the core to the wind-up. f The following examples illustrate but do not limit the invention.

EXAMPLE 1 A variable knop yarn-was produced by" a process as illustrated in. FIG. 1. The first filamentarycomponent comprised a drawn 167 decitex 30 filament poly(ethylene terephthalate) yarn. The second filamentary component comprised a drawn 22 decitex 7 filament poly(- hexamethylene adipamide) .yarn. The processing conditions were as follows:

Speed of false twist spindle 200,000 r.p.m.

Twist applied by spindle 2400 turns per metre Length of hotplate 28 inches Temperature of hotplate 210C Overfeed in false twist zone 0% Overfeed to wind-up 15% Nature of knop-fanning means Sintox ceramic guide EXAMPLE 2' A variable knop yarn was produced by a process similar to that illustrated in FIG. 1 except that a yarn relaxation zone was inserted between the nip roll assembly 27 and the wind-up package 33. The relaxation zone 3 comprised a heated tube followed by a nip roll assembly. The first component comprised a drawn 167 decitex 30 filament poly(ethylene terephthalate) yarn and the sescond component comprised a 22 decitex 7 filament poly(hexamethylene adipamide) yarn. The processing conditions were as follows:

Speed of false twist spindle 2l5,000 r.p.m.

Twist applied by spindle Z600 turns per metre Length of hotplate 28 inches Temperature of hotplate 200C Temperature of heated tube 180C Overfeed in false twist zone Overfeed in relaxation zone 15% Overfeed to wind-up 3% Nature of knop-forming means Sintox ceramic guide The knop yarn so produced contained to 16 knops per 10 yards of yarn, the knops being of length 7 8 to A inch and of diameter Vs to inch.

EXAMPLE 3 Speed of false twist spindle 250,000 r.p.m.

Twist applied by spindle 3200 turns per metre Length of hotplate 28 inches Temperature of hotplate 198C Overfeed in false twist zone 0% Overfeed to wind-up Two yarns produced as above but with S and Z twist spindles were twisted together to I turn per inch, steamed and thenknitted into a fabric of jersey construction. The resultant fabric was cross dyed to emphasize the knop effect.

A knop count was carried out by counting the number of knops in a 5 X 5 cm square of the fabric. The size of the knops was estimated visually on a graded scale in 4 which 1 is equivalent to small knops and 4 is equivalent to large knops.

The coefficient of friction of each ceramic guide was measured on a Shirley friction tester (banjo type) using a yarn spaced of 300 ft. per minute, the yarn having been produced by the above process but without the knop forming guide. The following results were obtained:

Coefficient of friction of ceramic guide Knop count Knot size What I claim is:

1. A process for making a variable knop yarn wherein a first filamentary component is passed from a feed means through, in sequence, a heating zone, a zone in which false twist is applied to the yarn and a knopforming zone to a withdrawing means and a second filamentary component is introduced in a region between said feed means and said zone in which false twist is applied in such a manner that it becomes wrapped around said first filamentary component, said second filamentary component being formed into knops in the knopforming zone by being rubbed back along said first component.

2. A process according to claim 1 wherein the second filamentary component is introduced between said feed means and said heating zone.

3. A process according to claim 1 wherein the first filamentary component is a polyester and the second filamentary component is a polyamide.

4. A process according to claim 1 wherein the false twist is applied by a twist pin.

5. A process according to claim I wherein the knops are formed by a means which comprise a friction device.

6. A process according to claim 5 wherein the friction device is a ceramic guide. 

1. A process for making a variable knop yarn wherein a first filamentary component is passed from a feed means through, in sequence, a heating zone, a zone in which false twist is applied to the yarn and a knop-forming zone to a withdrawing means and a second filamentary component is introduced in a region between said feed means and said zone in which false twist is applied in such a manner that it becomes wrapped around said first filamentary component, said second filamentary component being formed into knops in the knop-forming zone by being rubbed back along said first component.
 2. A process according to claim 1 wherein the second filamentary component is introduced between said feed means and said heating zone.
 3. A process according to claim 1 wherein the first filamentary component is a polyester and the second filamentary component is a polyamide.
 4. A process according to claim 1 wherein the false twist is applied by a twist pin.
 5. A process according to claim 1 wherein the knops are formed by a means which comprise a friction device.
 6. A process according to claim 5 wherein the friction device is a ceramic guide. 